.TH "FBB::CryptBuf" "3bobcat" "2005\-2020" "libbobcat\-dev_5\&.07\&.00" "Base class for DecryptBuf and EncryptBuf"

.PP 
.SH "NAME"
FBB::CryptBuf \- std::streambuf derived base class for DecryptBuf
and EncryptBuf 
.PP 
.SH "SYNOPSIS"
\fB#include <bobcat/cryptbuf>\fP
.br 
Linking option: \fI\-lbobcat \-lcrypto\fP 
.PP 
.SH "DESCRIPTION"
The class \fICryptBuf\fP inherits from \fIEoiBuf\fP and may therefore be
used as a base class of classes specializing \fIstd::streambuf\fP\&. It is used as
base class for the classes \fIDecryptBuf\fP and \fIEncryptBuf\fP, offering a
protected member for accessing cipher information\&.
.PP 
.SH "NAMESPACE"
\fBFBB\fP
.br 
All constructors, members, operators and manipulators, mentioned in this
man\-page, are defined in the namespace \fBFBB\fP\&.
.PP 
.SH "INHERITS FROM"
\fIEoiBuf\fP (and thus from: \fIstd::streambuf\fP)
.PP 
.SH "PROTECTED CONSTRUCTOR"

.PP 
Analogously to \fIstd::streambuf\fP only a protected constructor is
available\&.
.PP 
.IP o 
\fBCryptBuf(char const *type, size_t bufSize)\fP:
.br 
The type is a null\-terminated byte string specifying the de/encryption
method\&. E\&.g\&., \fIaes\-128\-cbc\fP\&. For an overview see the
\fBencryptbuf\fP(3bobcat) man\-page\&. The \fIbufSize\fP parameter defines
the initial size of the internally used buffer (defined by
\fIEoiBuf\fP)\&. 

.PP 
Copy and move constructors (and assignment operators) are not available\&.
.PP 
.SH "PROTECTED MEMBER FUNCTION"

.PP 
All members of \fIstd:streambuf\fP and \fIEoiBuf\fP are available, as
\fBFBB::CryptBuf\fP inherits from these classes\&.
.PP 
.IP o 
\fBEVP_CIPHER const *md() const\fP:
.br 
A pointer to the cipher information is returned\&.

.PP 
.SH "EXAMPLE"
Here is an example from the implementation of \fIEncryptBuf\(cq\&s\fP
constructor:
.PP 
.nf 
#include \(dq\&encryptbuf\&.ih\(dq\&

EncryptBuf::EncryptBuf(ostream &outStream, char const *type, 
                       string key, string const &iv, size_t size)
:
    CryptBuf(type, size),
    d_ctx(EVP_CIPHER_CTX_new()),
    d_encrypted(size + EVP_MAX_BLOCK_LENGTH, 0),
    d_iv(iv),
    d_key(key),
    d_outStream(outStream)
{
    prepareIV();

    if (
        not EVP_EncryptInit_ex(d_ctx, md(), 0, ucharPtr(d_key), 
                                               ucharPtr(d_iv))
    )
        throw Exception{ 1 } << \(dq\&Encrypt initialization failed\(dq\&;

    setp();
}






.fi 

.PP 
.SH "FILES"
\fIbobcat/cryptbuf\fP \- defines the class interface
.PP 
.SH "SEE ALSO"
\fBbobcat\fP(7), \fBdecryptbuf\fP(3bobcat), \fBencryptbuf\fP(3bobcat),
\fBeoibuf\fP(3bobcat), \fBeoi\fP(3bobcat)
.PP 
.SH "BUGS"
None Reported\&.
.PP 
.SH "BOBCAT PROJECT FILES"

.PP 
.IP o 
\fIhttps://fbb\-git\&.gitlab\&.io/bobcat/\fP: gitlab project page;
.IP o 
\fIbobcat_5\&.07\&.00\-x\&.dsc\fP: detached signature;
.IP o 
\fIbobcat_5\&.07\&.00\-x\&.tar\&.gz\fP: source archive;
.IP o 
\fIbobcat_5\&.07\&.00\-x_i386\&.changes\fP: change log;
.IP o 
\fIlibbobcat1_5\&.07\&.00\-x_*\&.deb\fP: debian package containing the
libraries;
.IP o 
\fIlibbobcat1\-dev_5\&.07\&.00\-x_*\&.deb\fP: debian package containing the
libraries, headers and manual pages;

.PP 
.SH "BOBCAT"
Bobcat is an acronym of `Brokken\(cq\&s Own Base Classes And Templates\(cq\&\&.
.PP 
.SH "COPYRIGHT"
This is free software, distributed under the terms of the 
GNU General Public License (GPL)\&.
.PP 
.SH "AUTHOR"
Frank B\&. Brokken (\fBf\&.b\&.brokken@rug\&.nl\fP)\&.
.PP